When a semiconductor device such as a MOSFET (MOS Field-Effect Transistor) is manufactured, impurity control of a semiconductor substrate is necessary. For impurity control in using a silicon carbide (SiC) substrate, a combination of ion implantation and activation annealing process generally is used, because a diffusion rate of impurity is very small. (Phys. Stat. Sol. (a) Vol. 162 (1997), p, 263, T. Kimoto, N. Inoue and H. Matsunami). For the impurity control of a silicon carbide (SiC) semiconductor device, ions to provide impurities are implanted into a required part of the silicon carbide (SiC) substrate by an ion implantation system. Next, the silicon carbide (SiC) substrate is annealed to activate impurities using a high temperature annealing apparatus such as a high frequency induction heating apparatus. (See Japanese Patent Application Laid-Open No. 2004-311696)